The present invention relates to a device for entangling filaments in a multifilament yarn, and more particularly to a device having a plurality of entangling nozzles for entangling the filaments with compressed air, the compressed air being fed via an air-feed beam to the entangling nozzles and the nozzles being closed by a baffle plate.
When drawing multifilament yarns of thermoplastic materials, such as polyamides, polyester, polypropylene, and polyethylene, particularly in connection with the drawing and warp beaming of such yarns, it is desirable for the yarns to be subjected to air entanglement before or after the drawing operation. Generally, an air jet is directed perpendicularly at each running yarn. The individual filaments are moved about by the air jet, contact each other, and thereby receive a certain cohesion among themselves. This process is generally referred to as interlacing or "entangling."
One entanglement process and a known entangling apparatus are described generally in U.S. Pat. No. 5,184,381, which corresponds to EP 488,070-A1.
Other devices for use in warping systems, draw-warping systems and warping frames, wherein a large number of multifilament yarns must be entangled simultaneously, are disclosed in EP 0 152 919 B1 (corresponding to U.S. Pat. Nos. 4,592,119 and 4,644,622) and DE 37 27 262 A1.
In the known devices, self-contained entangling nozzles are predominantly used. They generally have the shape of either a small tube, or a plate or block within which a thread channel is arranged. They are generally fastened directly to the air-feed beam.
In addition, turnable entangling nozzles are known, which can be opened on one side for the insertion of the thread and then turned to a closed position. In these turntable entangling nozzles it is possible, by the turning process, to shut off the compressed air during the threading process, but each entangling nozzle must be operated individually.
The threading process is very cumbersome, time-consuming and complicated in all the known devices and, as has been discovered in practice, must be repeated frequently. There is no assurance of dependable insertion of the thread. Furthermore, the feeding of the air, which must begin directly after the threading process and the starting of the thread, takes place in such devices at different time intervals and thereby leads to a poorer quality of the yarn. In a warping system in which 1,000 or even more threads are fed to a warp beam, two or three defective threads can result in rejection of the goods for the entire warp beam.
DE 35 23 711 A1 discloses a device for the air entanglement of a plurality of traveling threads, in which the nozzle shapes are formed directly in the air-feed beam. It must be strongly doubted whether the necessary qualities of the air feeding channel and thread channel can be obtained with this device. This device has baffle plates which comprise profiled bars or profiled cones which, after threading, must be fastened by hand on the air-feed beam by magnetic mounting or the like. In addition to requiring some means for cutting off the air supply, handling of these traverses is scarcely feasible in actual practice. Furthermore, the danger of injuring the surface of the impact plate on which the threads are entangled is very great due to the continuous thread transport. Rejects and thread breakage are expected with this device.
The disclosures of the above-mentioned prior art materials are expressly incorporated by reference.